# Tag Info

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Most batteries are impressively quiet when not loaded and really good when loaded with constant load. Batteries do have their own noise just like anything else, but i doubt you are interested in it in the context of motor controllers. On the other hand, their internal impedance can respond to a variable load (or charge current) in a rather complex way, ...

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They isolate RC filters. Each RC filter is a 1st order system with its transfer function. When you put opamp in between you do isolate, so that any forward section doesn't affect the backward section. The equivalent transfer function in Laplace domain is the product of all separate transfer functions. It's the way for study, you could have many other types ...

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Look at the schematic for a Sontec MEP250A. The boost/cut pots are fed by the buffered input on one side and an inverted version of the input on the other side. The wiper feeds the boost/cut signal to the filter input. After the signal passes through the filters, they are all summed in parallel to the inverting amp, which also serves as the output buffer. ...

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It's not a single-pole response, so 'cutoff frequency' isn't clearly defined, but let's assume its the -3dB point. Imagine you are calculating the response to VCEL3. You are correct to short all the other V sources. Clearly then, this puts additional elements in parallel with both R5 and R6 -- lowering the effective value of each. Thus the simple calculation ...

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Well, I am trying to analyze the following circuit: simulate this circuit – Schematic created using CircuitLab When we use and apply KCL, we can write the following set of equations: $$\text{I}_1=\text{I}_2+\text{I}_3\tag1$$ When we use and apply Ohm's law, we can write the following set of equations: $$\begin{cases} \text{I}_1=\frac{\text{V}_\text{i}... 0 Inserting that 2nd-harmonic filter between matching section, and low-pass section is improper design. This network looks like an inductor at the design frequency of 868Mhz. However, if you wish to knock down 2nd harmonic specifically, you can do so by modifying the low-pass filter's inductor to include a parallel capacitor. Doing this will impede the low-... 0 Please help me to solve this and correct if there are any mistakes in the component values at the required frequency 868MHz. Your 2nd harmonic filter looks likely to be the culprit. I can see that your final stage pi-filter is fine. My calculator indicates 9.168 nH and 3.6673 pF for the inductor and capacitors in that for 868 MHz with 50 Ω matching but, I ... 0 I'm not sure that is what the datasheet is saying, if you're looking at 8.3.12.1. It is the ac coupling capacitors in fig 89 that form the high pass filter with the resistors across the diff pair. For DC coupling, figure 90, no such filter exists... having a high pass filter in a directly coupled circuit doesn't make sense. I would suggest that the circuit ... 2 There's one thing you missed out: The gain-bandwidth product of the operational amplifier. Even if you are correct that the input filter has a cutoff frequency of 15.9 MHz in theory (neglecting the output impedance of the audio source), the actual cutoff is dominated by the operational amplifier because of the fact that the GBW of TL062 is 1 MHz. So it's ... 2 The impedance of an audio source would not be 0 ohms so the filter frequency would not be 16 MHz. That's why also 68nF you suggest is a bad idea, if source impedance is 1 kohm, the cutoff frequency would be 2 kHz. Typically audio inputs of professional devices have an RF blocking capacitor to filter out high frequency signals from getting to the amplifier ... 2 They are approximately equal. On one hand you have this: -$$\dfrac{I_{OUT}}{V_{IN(RIPPLE)}\cdot F_{SW}} \times \dfrac{V_{OUT}}{V_{IN}}$$And, on the other hand you have this: -$$\dfrac{I_{OUT}}{V_{IN(RIPPLE)}\cdot F_{SW}} \times D(1-D) For a synchronous buck converter, $D = \dfrac{V_{OUT}}{V_{IN}}$ so, it just means that (1-D) should be a value close ...

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Your schematic utilizes the capacitors as a filtering element at low frequencies. The choice of MLCC vs single-layer should make absolutely no difference as long as long as the MLCC version has the same voltage rating. MLCC capacitors can provide a slightly smaller footprint (more compact) with perhaps a slightly taller height. Unless you are operating ...

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$F_S$ is the sampling frequency. You want to remove it. $R_{ext}$ represents the impedance of the load you expect. $R_{ext}$ and the 560 ohm resistor are effectively in parallel to each other. If $R_{ext}$ is much larger than 560 ohms, then it matters very little. If the output of the filter goes to an op-amp input, $R_{ext}$ will be very large ...

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No, the Fs is the cutoff frequency you want for the filter. Rext is the load resistance of the device where the audio is being output. C is the capacitor for the lowpass filter. See the evaluation board schematics for example values for the passive filter.

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Are you aware of voltage divider rules and Thevenin's Theorem: - Can you see that R3 can merge into the value formed by the paralleling of R1 and R2 then, if rescaled the value of R1 and R2 it becomes the original circuit you drew.

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So far I've only encountered RC-filters, or more complicated ones that could however all be decomposed into RC-filters. These are normal RC filters, it's just that the R is made up of several Rs rather than one. We always consider power supplies to be 'AC ground'. The first filter has an effective R to ground that is just R1 parallel with R2, often written ...

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We really need a schematic of your charging circuit to be sure, but the likely problem is that you're undersampling the output. Your sensor is measuring the instantaneous current, but the current is being switched on and off by your PWM controller. If this is the case, the easiest solution would be to put a large capacitor across the sensor. The sensor has ...

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If you have enough oversampling you may can just average the measurements to get a rather stable and accurate result. The problem with measuring alternating signals like pwm is that if your sample rate doesn't match the frequency of the signal you tend to get unstable results depending on where the samples actually are taken. Another option would be to sync ...

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If the VFD manufacturer has provided advice about output filtering, that should be your primary advice. That will be based on their specific VFD design and its built-in motor protection features. The use of a 240 volt motor should provide a lot of safety margin for the winding insulation. Winding insulation is usually rated for 480 volt or even 600 volt ...

2

Whether to use a sine filter, or any filter is highly dependant on whether there are EMI concerns or insulation concerns. The high dv/dt of the leading edge of voltage waveforms from variable speed electric motor drives can lead to motor bearing failure, motor winding short circuits, and EMI compliance challenges.Passive output filters are used to mitigate ...

3

The sine filter is very expensive and bulky part of the drive. Without a choke and a shielded cable the VFD will work nice upto 35m, with unshielded cable even more. Then you add a choke. Lastly, when cables extend more than 200m a sine filter is employed. There is a substantial voltage drop on the filter, so the motor will lose power. There is a 10% voltage ...

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Choosing inductors isn't really delineated so much by visual construction style like you've framed your question with, but rather core geometry and core material. I would also note that 2 of these inductors are actually wound around a ferrite core, and their geometries are all very similar as well. The last one, the 'wound over plastic' inductor has the ...

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As the DAC is fed with samples at some rate, it can't directly output a perfect continuous analog sine wave from discrete samples, as the voltage is updated at some rate and between those updates the output is ideally constant and ideally the step is infinitely fast. Therefore the output waveform has steps at the rate of the sampling rate, which means there ...

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